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A002668 Continued cotangent for e.
(Formerly M1900 N0748)
12
2, 8, 75, 8949, 119646723, 15849841722437093, 708657580163382065836292133774995, 529026553215766321676623343348414600292754204772300344704877695232 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

REFERENCES

D. H. Lehmer, A cotangent analogue of continued fractions, Duke Math. J., 4 (1935), 323-340.

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Harry J. Smith, Table of n, a(n) for n=1,...,11

Eric Weisstein's World of Mathematics, Lehmer Cotangent Expansion

MATHEMATICA

b[1] = E; b[n_] := b[n] = (b[n-1]*Floor[b[n-1]]+1) / (b[n-1]-Floor[b[n-1]]); a[n_] := Floor[b[n]]; Table[a[n], {n, 1, 8}] (* From Jean-François Alcover, Jan 17 2012, after Pari *)

PROG

(PARI) { default(realprecision, 10000); bn=vector(11); bn[1]=exp(1); for(n=2, 11, bn[n]=(bn[n-1]*floor(bn[n-1]) + 1)/(bn[n-1] - floor(bn[n-1]))); for (n=1, 11, write("b002668.txt", n, " ", floor(bn[n]))); } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), May 04 2009]

CROSSREFS

Sequence in context: A064605 A132039 A204552 * A193205 A093062 A057984

Adjacent sequences:  A002665 A002666 A002667 * A002669 A002670 A002671

KEYWORD

nonn,easy,nice

AUTHOR

N. J. A. Sloane (njas(AT)research.att.com).

EXTENSIONS

More terms from J. O. Shallit.

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Last modified February 16 03:44 EST 2012. Contains 205860 sequences.